Variable-torque slip device



Oct. 15, 1968 J. KAPLAN 3,405,791

VARIABLE- TORQUE SLIP DEVICE Filed Aug. 25, 1966 4 Sheets-Sheet 1 FIG. FIG. 2 A

30a 30a 32 32a.

INVENTOR. JOSEPH KAPLAN ATTORNEY Oct. 15, 1968 J. KAPLAN 3,405,791

VARIABLE- TORQUE SLIP DEVICE Filed Aug. 25, 1966 4 heets-Sheet 2 INVENTOR. JOSEPH KAPLAN BY MZ7 ATTORNEY Oct. 15, 1968 J. KAPLAN 3,405,791

VARIABLE-TORQUE SLIP DEVICE Filed Aug. 25, 1966 4 Sheets-Sheet 5 FIG 7 INVENTOR. JOSEPH KAPLAN BY M4 4 ATTORNEY Oct. 15, 1968 J. KAPLAN VARIABLE-TORQUE SLIP DEVICE Filed Aug. 25, 1966 4 Sheets-Sheefc 4 vi R R M v? mw I!!! /A A k a mm h NTA x a 6 z MN xmm Em 3% o En Q\ INVENTOR. JOSEPH KAPLAN ATTORNEY United States Patent 3,405,791 VARIABLE-TORQUE SLIP DEVICE Joseph Kaplan, 39 Fair Lane, Jericho, N.Y.

Filed Aug. 25, 1966, Ser. No. 575,063 12 Claims. (Cl. 192-81) ABSTRACT OF THE DISCLOSURE This invention relates generally to limit-torque devices, and is especially concerned with such devices as include a spring-wrap slip element.

As is well known to those versed in the art, variabletorque slip devices find numerous applications in mechanisms requiring different levels of limit torque, say in the testing of motors or solenoids under varying load conditions. Such situations require extreme accuracy and repeatability of settings, which has heretofore been extremely dilficult to obtain.

Another very important area of application for vari able torque slip elements is in the field of tape or film winding mechanisms, where constant tape or film tension is required. Slip clutches and drag brakes are generally used for providing the limit torques for the take up and supply reels respectively. With a constant torque slip element, the tension of the tape will be lowest at the maximum reel diameter and highest at the minimum diameter. Consequently, in order to obtain constant tape tension the limit torque of the slip element must vary directly with the tape diameter of the respective reel. This variable torque slip device is suitable for fulfilling this function.

Accordingly, it is an important object of the present invention to provide a variable-torque slip device of the type described, wherein substantially infinitely variable torque settings are accurately and repeatably obtainable.

It is a further object of the present invention to provide a variable-torque slip device having the advantageous characteristics mentioned in the preceding paragraph, which is extremely simple in construction, durable and reliable throughout a long useful life, and which can be economically manufactured for sale at a reasonable price.

It is a more particular object of the present invention to provide a variable-torque slip device of the type described wherein a rotary member in the nature of a shaft, brake drum or the like is encompassed by a helical spring frictionally circumposed about the rotary member, and wherein spaced portions of the spring are displaced angularly relative to each other to effect opening and closing of the spring for varying the friction torque applied by the spring to the rotary member.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.

The invention accordingly consists of the features of construction, combinations of elements, and arrangements of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claims.

In the drawings:

FIGURE 1 is a side elevational view showing a variable-torque slip device constructed in accordance with the teachings of the present invention;

FIGURE 2 is a sectional elevational view taken generally along the line 22 of FIGURE 1;

FIGURE 3 is a side elevational view showing a slightly modified variable-torque slip device of the present invention;

FIGURE 4 is a sectional elevational view taken generally along the line 4-4 of FIGURE 3;

FIGURE 5 is a plan view showing a variable-torque slip device of the present invention in operative association with a supply reel for varying the torque applied thereto responsive to the diameter of coiled material on the reel; I

FIGURE 6 is an elevational view of the variable-torque slip device of FIGURE 5;

FIGURE 7 is a longitudinal elevational view, partly in section, illustrating an embodiment of variable-torque slip device for a take-up reel, constructed in accordance with the teachings of the present invention.

FIGURE 8 is a plan view, partly in section, showing a further embodiment of variable-torque slip device of the present invention for a take-up reel, as taken along the line 8--8 of FIGURE 9; and

FIGURE 9 is a sectional view taken generally along the line 99 of FIGURE 8.

Referring now more particularly to the drawings, and specifically to FIGURES 1 and 2 thereof, a slip device is there generally designated 20, and includes a supporting structure 21 having a base 22 and spaced upstanding supports or journal pedestals 23 and 24. A rotary member 25 extends through the supports 23 and 24, including a shaft 26 having spaced portions journaled for axial rotation in respective supports. The rotary member 25 includes an enlargement, collar or drum 27 keyed to the shaft 26 between the supports 23 and 24, for rotation therewith.

Circumposed about the drum 27 of rotary member 25, in frictional or gripping engagement therewith, is a helically coiled spring 30 having at opposite ends outstanding terminal regions 31 and 32. A holding member or pin 33- is fixed to the support 24, projecting inward therefrom for abutting engagement with the terminal spring region 31.

Adjacent to the terminal spring region 32 there is provided a control member 35, including an arm 36 mounted for swinging or rotative movement about the axis of rotary member 25 and extending radially therefrom. Carried by the arm 36 of the control member is an abutment or post 37 projecting from the arm for movement therewith into abutting engagement with the terminal spring region 32. Thus the control member 35 may be swung about the axis of shaft 26, in the direction of arrow 38 in FIGURE 2, to open or spread the helical spring 30 and reduce frictional gripping engagement of the spring with respect to the drum 27. In this manner, the terminal regions 31 and 32 of spring 30 are angularly displaced relative to each other to vary frictional engagement of the spring with the drum, which frictional engagement is accurately controllable and repeatable for applying a limit torque through the rotary member 25.

The variable-torque slip device shown in FIGURES 3 and 4 is essentially similar to that of FIGURES l and 2, but employs a plurality of spring elements. More particularly, the variable-torque slip device 20a of FIGURES 3 and 4 includes a supporting structure, generally designated 21a having a pair of spaced support members 23a and 24a rigidly connected together by a plurality of parallel spaced, generally cylindrically arranged tie members 22a. Extending rotatably through the support structure 21a is a rotary member 25a, being journaled for axial rotation at spaced locations in the support members 23a and 24a. The rotary member 25a may include a shaft 26a and an enlargement or drum 27a carried by the shaft between the support members 23a and 24a- A plurality of helically coiled springs are arranged in axially aligned adjacent relation circumposed about the drum 27a in frictional engagement therewith. The several springs are each designated 30a, and each formed with its terminal regions bent to project generally radially outward, as at 31a and 32a.

A control member is generally designated 35a, and includes a pair of spaced plates and 41, respectively adjacent to support members 23a and 24a and mounted for rotation about the axis of rotary member 25a and relative thereto. In the illustrated embodiment the controlmember plate 40 is located inward of the support member 23a, between the latter and support member 24a, while the control-member plate 41 is located outward of the support member 24a, on the side thereof remote from the support member 23a. A plurality of elongate tie members 42 extend rigidly between and connect the plates 40 and 41, to mount the control member for unitary swinging or rotative movement about the axis of shaft 26a. The ties or connecting members 42 of the control member 35a may be located in the same cylindrical arrangement as the ties or connecting members 22a, so that relative rotation of the control member 35a is limited by abutting engagement between the connecting members 220 and 42. A control arm 36a may project radially from one plate 40 for effecting rotation of the control member 35a. As best seen in FIGURE 4, the terminal spring regions 31a are in abutting engagement with one of the fixed tie members 22a, while the other terminal spring regions 32a are in abutting engagement with one of the movable tie members 42 of the control member 35a. Thus, rotative or swinging movement of control member 35a, as by swinging of arm 36a, effects angular displacement of the terminal regions 31a and 32a of the several springs 30a to open or distend the springs and reduce their frictional engagement with the drum 27a. Thus, any selected limit torque may be applied to the rotary member 25a in generally the same manner as described hereinbefore in connection with the embodiment of FIGURES 1 and 2.

Referring now to FIGURES 5 and 6, a variable-torque slip device is there generally designated 20b and carried by a mounting structure or plate 45, fixed on one side thereof. Interiorly of the slip device 20b is a rotary member .of the type described in connection with FIGURES 1-4, which may project through the mounting plate 45 and on its projecting end carry a spool 46 for uncoiling of tape 47, or the like. Extending from the slip device 20b is a control arm 36b for controlling the drag torque of the rotary member.

Sensing means is generally designated and may include a shaft 51 extending rotatably through the mounting plate 45 and carrying on one end adjacent to the spool 46 a crank arm 48. The crank arm 48 is provided with a rotatable wheel or follower roll 49 engageable with the coiled material 47 on the spool 46 for sensing the diameter of the coiled material and rotating or swinging about the axis of shaft 51 in response to the diameter of coiled material. Suitable spring means 52 may be circumposed about the shaft 51 having its opposite ends connected to the mounting plate 45 and arm 48 for maintaining the roll 49 in rolling engagement with the material 47.

The shaft 51 is provided, remote from the arm 48, with a crank 53, to which a link or connecting member 54 is eccentrically connected. The opposite end of the link 54 is connected to the distal end of the control arm 36b. In this manner, the angular motion of the crank arm 48, efiected in response to variations in the diameter of the coiled material 47, will cause an equivalent angular motion of the control arm 3617. Thus, it will now be appreciated that the control arm 36b is rotated in accordance with the diameter of coiled material 47 through the sensing means 50, crank 53 and connecting link 54. In this til manner, accurate control of drag torque applied to the shaft of a spool 46 is automatically maintained in accordance with the diameter of material 47 coiled about the shaft.

In the embodiment of FIGURE 7, there are a pair of fixed, spaced support members or plates 23c and 24c, and a rotary member 250 extending therebetween and journaled therein. The rotary member includes a shaft 260 and an enlargement ordrum 270 on the shaft. A helically coiled spring 300 is frictionally circumposed about the drum 27c and has its terminal regions bent to extend radially outward, as at 31c and 32c. An input gear 56 is journaledon the shaft 260 for rotation therewith and relative thereto, and includes a holding member or longitudinal extension 330 located for abutting engagement with terminal spring region 31c. Iournaled on the shaft 260 on the opposite side of spring 30c as gear 56 is a clutch reaction element or roll 57 carrying a longitudinal extension or control element 37c projecting for abutting engagement with the spring terminal region 32c. The rotary reaction element 57 is provided with an opposite longitudinal extension 58 disposed in facing spaced relation with the end portion of holding member 33c, the latter having on its end portion an oblique cam surface 59.

Also mounted on the shaft 26c adjacent to the reaction element 57, is a cam actuator carrier or roll 60. The roll 60 is mounted for rotation about the shaft 26c, relative thereto, and for linear movement longitudinally of the shaft. The carrier 60 carries a cam-actuating element or follower 66 which is engageable between the cam surface 59 of holding member 330 and the extension 58 carried bythe reaction element, which also carries the control member 37c.

An additional carrier roll 61 is mounted on the shaft 26c for rotation relative thereto. Further, the carrier member 61 is constrained to longitudinal sliding movement along the shaft 26c by a pin-in-slot connection 62. Thus, the carrier 61 is constrained to pure longitudinal or linear movement along the shaft 260 while the latter may rotate, and the carrier 60 may rotate with or relative to the shaft 26c as well as move linearly with the carrier 61.

A control crank 63 is journaled on shaft 260 for rotation relative to the shaft and is constrained against movement longitudinally of the shaft. Provided on the control crank 63 is a cam surface 64 facing toward the carrier 61, and a cam follower 65 is provided on the carrier 61 in following engagement with the surface 64.

Thus, angular shifting or rotation of control crank 63 effects longitudinal shifting of carrier 61 by the movement of follower 65 on inclined cam surfaces 64. This shifts carrier 60 and cam actuator 66 longitudinally of the shaft to effect relative displacement between the hold ing member 33c and control member 370 for opening or closing the spring 30c about the drum 27c to vary frictional engagement torque between the spring and drum. During such movement, the gear 56 may be driven and the drum 270, spring 300, reaction element 57 and carrier 60 all rotate, while the carrier 61 does not rotate but only moves linearly. The control crank 63 will rotate relative the shaft 260, as mentioned above, thus effecting, by means of its cam surface 64, the linear movement of the carrier 61 and the resultant movement of the reaction element 57 that will cause the relative unwinding of the spring 30c thus reducing the amount of torque required to rotate the shaft 260. Rotation of the crank 63 may be accomplished through the means of a linkage (not shown), in the manner described in the preceding embodiments. Such linkage may be connected to the crank 63 by'means of the pin 63a. This arrangement is suitable for a take-up reelin which the tape is to be wound at constant tension.

Referring now to FIGURES 8 and 9, a pair of mounting plates are shown at 23a and 24d in spaced facing relation. A drive shaft 67 extends between and is journaled in the mounting plates 23d and 24d carrying a pair of spaced drive gears 68 and 69 keyed to the drive shaft. A driven shaft 26d extends between and is journaled in the mounting plates 23d and 24d, substantially parallel to the drive shaft 67, and carries an enlargement or drum 27d keyed to the driven shaft. Rotatably circumposed about the driven shaft are gears 70 and 71 on opposite sides of the drum 27d, the former carrying an extension or holding member 33d extending longitudinally of and over the drum 27d, while the latter carries a control member extension 37d extending longitudinally of and over the drum 27d. A helically coiled spring 30d is frictionally circumposed about the drum 27d and formed with outstanding terminal regions 31d and 32d in respective abutting engagement with holding member 33d and control member 37d.

An idler gear 72 is rotatably carried by the mounting plate 23d and in meshing engagement and between the gears 68 and 70 to drive the latter gear in accordance with rotation of the shaft 67. The idler gear 72 is carried by a shaft 73 rotatable about a fixed axis.

Interposed between the gears 69 and 71, in meshing engagement therewith is an idler gear 74, mounted for rotation on a shaft 75 which is moveable with a control crank 76 carried on the shaft 67 for swinging movement about the axis thereof.

Thus, upon rotation of the shaft 67 by a suitable drive means, the gears 68, 72 and 70 combine to define a positive transmission for effecting rotation of the holding member 33d and consequent rotation of the spring end region 310! at a speed proportional to that of the driving speed. The gears 69, 74 and 71 combine to define an additional transmission chain for effecting rotation of the control member 37d and its adjacent abutting spring end region 32d. However, by movement of the idler gear 74 with control crank 76 relative to the driven gear 71, the driven gear and its control member 37d are displaced angularly about the axis of driven shaft 26d relative to the holding member 33d. This relative displacement causes opening or spreading of the spring 30d to vary the frictional engagement of the spring with the drum 27d. Of course, control of the crank 76 may be made responsive to a coil diameter or other variable to be sensed, as desired, as by a link or control arm 77 pivotally connected to the shaft 75 which is freely movable in the enlarged opening 78 provided in plate 24d. This arrangement is also suitable for a take-up reel.

From the foregoing it is seen that the present invention provides a variable-torque slip device which fully accomplishcs its intended objects and is well adapted to meet practical conditions of manufacture, installation and use.

Although the present invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be made within the spirit of the invention and scope of the appended claims.

What is claimed is:

1. A variable-torque slip device comprising a rotary member, a helical spring circumposed about said rotary member in constant self energized frictional engagement therewith, a holding member operatively connected to one portion of said spring, and a swingable control member operatively connected to another portion of said spring for angularly displacing said portions relative to each other to vary the friction torque applied to said rotary member.

2. A variable-torque slip device according to claim 1, said spring being generally coaxial with the axis of rotation of said rotary member, and said control member being swingable about said axis for displacing said other spring portion angularly about said axis relative ot said one spring portion.

3. A variable-torque slip device according to claim 2, said spring portions being at opposite ends of said spring and comprising outstanding terminal spring regions.

4. A variable-torque slip device according to claim 3, said holding and control members being in abutting engagement with respective terminal spring regions.

5. A variable-torque slip device according to claim 4, in combination with a second helical spring for coaxial circumposition about said rotary member in frictional engagement therewith, and a second pair of outstanding terminal regions on said second spring respectively engageable with said holding and control members, for angularly displacing one of said second pair of terminal regions relative to the other of said second pair of terminal regions simultaneously with relative displacement of said first-mentioned pair of terminal regions.

6. A variable-torque slip device according to claim 4, in combination with a rotatable coil spool operatively connected to said rotatable member for rotation therewith, sensing means for sensing the coil diameter on said spool, and operating means connected between said sensing means and control member to swing the latter responsive to said coil diameter.

7. A variable-torque slip device according to claim 6, said sensing means comprising a swingable follower arm engageable with said coil and angularly displaced thereby, and said operating means comprising a connecting link between said follower arm and control member.

8. A variable-torque slip device according to claim 4, said holding member being rotatable about said axis for rotation with said spring, and said control member being rotatable about said axis for rotation with said spring and relative to said holding member for varying the relative angular displacement between said terminal spring regions and the friction applied to said rotary member.

9. A variable-torque slip device according to claim 8, in combination with cam means operatively connected between said holding and control members for rotation therewith and longitudinally movable relative thereto for effecting said relative angular displacement.

10. A variable-torque slip device according to claim 8, in combination with drive means, a first transmission connected between said drive means and said holding member for rotating the latter in accordance with said drive means, and a second transmission connected between said drive means and control member for rotating said control member, said second transmission comprising a drive gear connected to said drive means, a driven gear rotat able coaxially with and connected to said control member, a intermediate idler gear connected in meshing engagement between said drive and driven gears, and mounting means mounting said idler gear for movement of its axis relative to said drive and driven gears, to vary the relative displacement of said holding and control members.

11. A variable-torque slip device comprising a rotary member, a helical spring circumposed about said rotary member in frictional engagement therewith, a holding member coaxially rotatable relative to said rotary member and operatively connected to one portion of said spring, a control member coaxially rotatable relative to said rotary member and operatively connected to another portion of said spring, cam means on at least one of said holding and control members, and cam-actuating means in operative engagement with said cam means mounted for rotation coaxially with and shifting movement longitudinally of said rotary member for actuating said cam means during rotation thereof to angularly displace said members relative to each other.

12. A variable-torque slip device comprising a rotary member, a helical spring circumposed about said rotary member in frictional engagement therewith, a holding member operatively connected to one portion of said spring and rotatable coaxially with said rotary member, a control member operatively connected to another portion of said spring and rotatable coaxially with said rotary member and relative thereto for angularly displacing said spring portions relative to each other to vary the friction applied to said rotary member, a drive means, a first transmission connected between said drive means .and said holding member for rotating the latter in accordance with said drive means, and a second transmission connected between said drive means and control member for rotating said control member, said second transmission means comprising a drive gear connected to said drive means, a driven gear rotatable coaxially with and connected to said control member, an intermediate idler gear connected in meshing engagement between said drive and driven gears, and mounting means mounting said idler gear formovernent of its axis relative to said drive and driven gears, to vary the relative displacement of said holding and control members.

589,779 9/1897 Hall I 18877 5 1,304,882 5/1919 Johnson 188 77 3,117,742 1/1964 Trombetta 242156.'2

FOREIGN PATENTS 369,239 7 3/ 1932 Great Britain.

MARTIN P. SCHWADRON, Primary Examiner.

C. ,M. LEEDOM, Assistant Examiner.- 

